引言减水剂是使用数量最大、最广泛、效果最佳的混凝土外加剂。在混凝土中掺入少量（一般占水泥重量的0．2～2％）减水剂后，可以达到如下技术经济效果：保持和易性不变，减少单位用水量5～25％，提高混凝土早期和后期强度；保持用水量不变，增大坍落度10～20cm，满足泵送、大 Introduction Water reducers are the most used, most extensive, and most effective concrete admixtures. By incorporating a small amount of water-reducing agent (usually accounting for 0.2-2% of the cement weight) in the concrete, the following technical and economic effects can be achieved: keeping the workability constant, reducing the unit water consumption by 5-25%, and improving the early concrete And later strength; maintain the same amount of water, increase the slump 10 ~ 20cm, to meet the pumping, large